U.S. patent number 6,548,458 [Application Number 10/008,510] was granted by the patent office on 2003-04-15 for succinimide-acid compounds and derivatives thereof.
This patent grant is currently assigned to Ethyl Corporation. Invention is credited to John T. Loper.
United States Patent |
6,548,458 |
Loper |
April 15, 2003 |
Succinimide-acid compounds and derivatives thereof
Abstract
Succinimide-acid compounds prepared by reaction of
hydrocarbyl-substituted succinic acylating agents with alpha-omega
amino acids are disclosed, as well as derivatives thereof useful as
lubricity additives, lubricant dispersants, friction modifiers,
liquid hydrocarbonaceous fuel detergents, antioxidants and alkali
and/or alkaline-earth metal detergents.
Inventors: |
Loper; John T. (Richmond,
VA) |
Assignee: |
Ethyl Corporation (Richmond,
VA)
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Family
ID: |
24243506 |
Appl.
No.: |
10/008,510 |
Filed: |
November 8, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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561796 |
May 1, 2000 |
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Current U.S.
Class: |
508/291; 44/331;
548/547; 44/348; 508/231; 508/290; 548/546; 508/221 |
Current CPC
Class: |
C07D
207/412 (20130101); C10M 159/12 (20130101); C10M
159/20 (20130101); C10L 1/2366 (20130101); C10L
1/2364 (20130101); C10L 10/08 (20130101); C10L
10/06 (20130101); C10L 1/2368 (20130101); C07D
207/408 (20130101); C10L 1/224 (20130101); C10L
1/238 (20130101); C10M 2215/086 (20130101); C10N
2010/02 (20130101); C10N 2030/06 (20130101); C10N
2010/04 (20130101); C10M 2215/28 (20130101); C10N
2060/09 (20200501); C10N 2040/25 (20130101) |
Current International
Class: |
C10L
1/238 (20060101); C10L 1/224 (20060101); C10L
1/10 (20060101); C10L 10/00 (20060101); C10L
1/236 (20060101); C07D 207/412 (20060101); C10L
10/04 (20060101); C07D 207/404 (20060101); C10M
133/00 (20060101); C10M 159/12 (20060101); C10M
133/16 (20060101); C10M 159/00 (20060101); C10M
159/20 (20060101); C07D 207/00 (20060101); C10M
133/58 (); C10L 001/22 (); C07D 207/416 () |
Field of
Search: |
;508/290,291 ;44/348
;548/546,547 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1 670 239 |
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Jan 1971 |
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DE |
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0 721 010 |
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Jul 1996 |
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EP |
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2 044 305 |
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Feb 1971 |
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FR |
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1994/06003782A |
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Jan 1994 |
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JP |
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WO94/21607 |
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Sep 1994 |
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WO |
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WO97/22582 |
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Jun 1997 |
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WO |
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WO00/02990 |
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Jan 2000 |
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WO |
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Other References
P Weichert; The Effects of Succinyl-GABA-Derivatives on
Experimental Seizures; & Monogr. Neural Sci. (1980), volume
Date 1978, 5 (Epilepsy), STN Database Chemabs Online!; Database
accession No. 96:115824 XP002174838 (Chemical Abstracts Service,
Columbus, OH). .
John P. Devlin; Antibiotic Actinonin. III. Synthesis of Structural
Analogs of Actinonin by the Anhydride-Imide Method; Database
Chemabs Online!; STN Database Accession No. 83:59249 XP002174839;
(Chemical Abstracts Service, Columbus, OH)..
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Primary Examiner: McAvoy; Ellen M.
Attorney, Agent or Firm: Rainear; Dennis H.
Parent Case Text
This application is a division of application Ser. No. 09/561,796,
filed May 1, 2000, now abandoned.
Claims
I claim:
1. A succinimide-acid derivative prepared by reacting a
succinimide-acid compound comprising the reaction product of a
hydrocarbyl-substituted succinic acylating agent and an amino acid
represented by the formula: ##STR4##
wherein R is an alkyl group, having from 1 to 12 carbon atoms or an
aryl group and a compound comprising at least one primary or
secondary amine capable of reacting with said succinimide-acid.
2. The succinimide-acid derivative of claim 1, wherein the
hydrocarbyl-substituted acylating agent is an alkenyl succinic
anhydride comprising from 8 to 100 carbon atoms in the alkenyl
group.
3. The succinimide-acid derivative of claim 1, wherein the
hydrocarbyl-substituted succinic acylating agent comprises a
polyolefin-substituted succinic acylating agent.
4. The succinimide-acid derivative prepared of claim 1, wherein the
hydrocarbyl-substituted succinic acylating agent comprises an
olefin copolymer grafted with maleic anhydride.
5. The succinimide-acid derivative of claim 1, wherein the amine
comprises at least one member selected from the group consisting of
polyamines and hydroxy amines.
6. The succinimide-acid derivative of claim 5 wherein the amine
comprises a polyethylene polyamine selected from the group
consisting of diethylene triamine, triethylene tetramine,
tetraethylene pentamine, pentaethylene hexamine, heavy polyamines
and mixtures thereof.
7. The succinimide-acid derivative of claim 5 wherein the amine
comprises at least one hydroxyamine selected from the group
consisting of aminoethylethanolamine, aminopropyl diethanolamine,
3-amino-1,2-propanediol, tris(hydroxymethyl)aminomethane,
2-amino-1,3-propanediol, ethanolamine, diethanolamine and partially
propoxylated hexamethylene diamine.
8. The succinimide-acid derivative of claim 5 wherein the amine
comprises at least one member selected from the group consisting of
N-arylphenylenediamines, aminothiazoles, aminocarbazoles,
aminoindoles, aminopyrroles, amino-indazolinones,
aminomercaptotriazoles, aminoperimidines, aminoalkyl imidazoles and
aminoalkyl morpholines.
9. The succinimide-acid derivative of claim 5 wherein the amine
comprises aminoguanidine.
10. The succinimide-acid derivative of claim 5 wherein the amine
comprises a polyamine having at least one primary or secondary
amino group and at least one tertiary amino group in the
molecule.
11. The succinimide-acid derivative of claim 10 wherein the amine
comprises at least one member selected from the group consisting of
N,N,N",N"-tetraalkyldialkylenetriamines,
N,N,N',N"-tetraalkyltrialkylenetetramines, N,N,N',N",N'"
-pentaalkyltrialkylenetetramines, and
tris(dialkylaminoalkyl)aminoalkylmethanes, wherein the alkyl groups
are the same or different and contain no more than about 12 carbon
atoms each.
12. The succinimide-acid derivative of claim 10 wherein the amine
comprises at least one member selected from the group consisting of
dimethylaminopropylamine and N-methyl piperazine.
13. The succinimide-acid derivative of claim 1 wherein the amine
comprises an amine dispersant.
14. The succinimide-acid derivative of claim 13 wherein the amine
dispersant comprises at least one member selected from the group
consisting of mono-succinimides, bis-succinimides, Mannich
condensation products, hydrocarbyl amines and polyether amines.
15. A lubricant composition comprising an oil of lubricating
viscosity and from about 0.1 to 10 wt. %, based on the total weight
of the lubricant composition, of the succinimide-acid derivative of
claim 2 with at least one member selected from the group consisting
of polyhydroxy compounds, compounds comprising at least one primary
or secondary amine capable of reacting with said succinimide-acid,
and mixtures thereof.
16. A lubricant composition comprising an oil of lubricating
viscosity and from about 0.1 to 10 wt. %, based on the total weight
of the lubricant composition, of the succinimide-acid derivative of
claim 3 with at least one member selected from the group consisting
of polyhydroxy compounds, compounds comprising at least one primary
or secondary amine capable of reacting with said succinimide-acid,
and mixtures thereof.
17. A lubricant composition comprising an oil of lubricating
viscosity and from about 0.1 to 10 wt. %, based on the total weight
of the lubricant composition, of the succinimide-acid derivative of
claim 4 with at least one member selected from the group consisting
of polyhydroxy compounds, compounds comprising at least one primary
or secondary amine capable of reacting with said succinimide-acid,
and mixtures thereof.
18. A fuel composition comprising a hydrocarbonaceous fuel and from
about 0.1 to 10 wt. %, based on the total weight of the fuel
composition, of the succinimide-acid derivative of claim 2 with at
least one member selected from the group consisting of polyhydroxy
compounds, compounds comprising at least one primary or secondary
amine capable of reacting with said succinimide-acid, and mixtures
thereof.
19. A fuel composition comprising a hydrocarbonaceous fuel and from
about 0.1 to 10 wt. %, based on the total weight of the fuel
composition, of the succinimide-acid derivative of claim 3 with at
least one member selected from the group consisting of polyhydroxy
compounds, compounds comprising at least one primary or secondary
amine capable of reacting with said succinimide-acid, and mixtures
thereof.
20. A fuel composition comprising a hydrocarbonaceous fuel and from
about 0.1 to 10 wt. %, based on the total weight of the fuel
composition, of the succinimide-acid derivative of claim 4 with at
least one member selected from the group consisting of polyhydroxy
compounds, compounds comprising at least one primary or secondary
amine capable of reacting with said succinimide-acid, and mixtures
thereof.
21. A method of improving the fuel economy of an internal
combustion engine, said method comprising using as the crankcase
lubricating oil for said internal combustion engine lubricant
composition of claim 15, wherein said succinimide-acid derivative
is present in the lubricant composition in an amount sufficient to
improve the fuel economy of the internal combustion engine using
said crankcase lubricating oil, as compared to said engine operated
in the same manner and using the same crankcase lubricating oil
except that the oil is devoid of said succinimide-acid
derivative.
22. The method of claim 21 wherein the hydrocarbyl-substituted
acylating agent is an alkenyl succinic anhydride comprising from 12
to 30 carbon atoms in the alkenyl group.
23. The method of claim 21 wherein the succinimide-acid derivative
is prepared by reacting a succinimide-acid compound and an amine
compound comprising at least one primary or secondary amine capable
of reacting with said succinimide-acid.
24. The method of claim 23 wherein said amine comprises at least
one hydroxy amine selected from the group consisting of
aminoethylethanolamine, aminopropyl diethanolamine,
3-amino-1,2-propanediol, tris(hydroxymethyl)aminomethane,
2-amino-1,3-propanediol, ethanolamine, diethanolamine and partially
propoxylated hexamethylene diamine.
25. The method of claim 23 wherein said amine comprises
aminoguanidine.
26. The method of claim 21 wherein the succinimide-acid derivative
is prepared by reacting a succinimide-acid compound and a
polyhydroxy compound.
27. The method of claim 26 wherein said polyhydroxy compound
comprises at least one fully-alkoxylated amine selected from the
group consisting of propoxylated hexamethylene diamine,
propoxylated triethylene tetramine,
tetrakis(2-hydroxypropyl)ethylenediamine and triethanolamine.
28. The method of claim 26 wherein said polyhydroxy compound
comprises at least one polyol selected from the group consisting of
glycerol, sorbitol, pentaerythritol, mannitol and polyalkylene
glycols.
29. The method of claim 21 wherein said succinimide-acid derivative
is present in the crankcase lubricating oil in an amount of from
0.1 to 3 weight percent based on the total weight of the crankcase
lubricating oil.
30. A method of improving the fuel economy of a vehicle, said
method comprising using as a lubricant composition for said vehicle
the lubricant composition of claim 15, wherein said
succinimide-acid derivative is present in the lubricant composition
in an amount sufficient to improve the fuel economy of the vehicle
using said lubricating oil composition, as compared to said vehicle
operated in the same manner and using the same lubricant
composition except that the composition is devoid of said
succinimide-acid derivative.
31. The method of claim 30 wherein the hydrocarbyl-substituted
acylating agent is an alkenyl succinic anhydride comprising from 12
to 30 carbon atoms in the alkenyl group.
32. The method of claim 30 wherein the succinimide-acid derivative
is prepared by reacting a succinimide-acid compound and an amine
compound comprising at least one primary or secondary amine capable
of reacting with said succinimide-acid.
33. The method of claim 32 wherein said amine comprises at least
one hydroxy amine selected from the group consisting of
aminoethylethanolamine, aminopropyl diethanolamine,
3-amino-1,2-propanediol, tris(hydroxymethyl)aminomethane,
2-amino-1,3-propanediol, ethanolamine, diethanolamine and partially
propoxylated hexamethylene diamine.
34. The method of claim 32 wherein said amine comprises
aminoguanidine.
35. The method of claim 30 wherein the succinimide-acid derivative
is prepared by reacting a succinimide-acid compound and a
polyhydroxy compound.
36. The method of claim 35 wherein said polyhydroxy compound
comprises at least one fully-alkoxylated amine selected from the
group consisting of propoxylated hexamethylene diamine,
propoxylated triethylene tetramine,
tetrakis(2-hydroxypropyl)ethylenediamine and triethanolamine.
37. The method of claim 35 wherein said polyhydroxy compound
comprises at least one polyol selected from the group consisting of
glycerol, sorbitol, pentaerythritol, mannitol and polyalkylene
glycols.
38. The method of claim 30 wherein said lubricant composition is a
crankcase oil present in the crankcase of said vehicle.
39. The method of claim 30 wherein said lubricant composition is a
lubricant composition present in the automotive drivetrain of said
vehicle.
40. The method of claim 30 wherein said succinimide-acid derivative
is present in the lubricant composition in an amount of from 0.1 to
3 weight percent based on the total weight of the lubricant
composition.
41. A method of reducing wear in an internal combustion engine
comprising using as the crankcase lubricating oil for said internal
combustion engine the lubricant composition of claim 15, wherein
said succinimide-acid derivative is present in an amount sufficient
to reduce the wear in an internal combustion engine operated using
said crankcase lubricating oil, as compared to the wear in said
engine operated in the same manner and using the same crankcase
lubricating oil except that the oil is devoid of said
succinimide-acid derivative.
42. A method of improving the oxidation stability of a lubricating
oil composition, said method comprising adding to an oil of
lubricating viscosity an oxidation stability improving amount of
the succinimide-acid derivative of claim 2, wherein said amount of
said succinimide-acid derivative is effective to improve the
oxidative stability of the lubricating oil composition, as compared
to the same lubricating oil composition except that it is devoid of
said succinimide-acid derivative.
43. The method of claim 42 wherein the hydrocarbyl-substituted
acylating agent is an alkenyl succinic anhydride comprising from 12
to 30 carbon atoms in the alkenyl group.
44. The method of claim 42 wherein the amine comprises at least one
member selected from the group consisting of
N-arylphenylenediamines, aminothiazoles, aminocarbazoles,
aminoindoles, aminopyrroles, amino-indazolinones,
aminomercaptotriazoles, aminoperimidines, aminoalkyl imidazoles and
aminoalkyl morpholines.
45. The method of claim 42 wherein the amino-acid comprises at
least one aromatic amino acid.
46. The method of claim 42 wherein said succinimide-acid derivative
is present in the lubricating oil composition in an amount of from
0.1 to 3 weight percent based on the total weight of the
lubricating oil composition.
47. A method of reducing wear in the fuel system of an internal
combustion engine comprising using as the fuel for use in said
internal combustion engine the fuel composition of claim 18,
wherein said succinimide-acid derivative is present in the fuel in
an amount sufficient to reduce the wear of the fuel system, as
compared to the wear in said fuel system operated in the same
manner and using the same fuel except that said fuel is devoid of
said succinimide-acid derivative.
48. The method of claim 47 wherein the hydrocarbyl-substituted
acylating agent is an alkenyl succinic anhydride comprising from 12
to 30 carbon atoms in the alkenyl group.
49. The method of claim 47 wherein said derivative is prepared by
reacting the succinimide-acid with at least one amine and wherein
said amine comprises at least one hydroxy amine selected from the
group consisting of aminoethylethanolamine, aminopropyl
diethanolamine, 3-amino-1,2-propanediol,
tris(hydroxymethyl)aminomethane, 2-amino-1,3-propanediol,
ethanolamine, diethanolamine and partially propoxylated
hexamethylene diamine.
50. The method of claim 47 wherein said derivative is prepared by
reacting the succinimide-acid with at least one polyhydroxy
compound and wherein said polyhydroxy compound comprises at least
one polyol selected from the group consisting of glycerol,
sorbitol, pentaerythritol, mannitol and polyalkylene glycols.
51. A lubricant composition comprising an oil of lubricating
viscosity and from about 0.1 to 10 wt. %, based on the total weight
of the lubricant composition, of a succinimide-acid derivative,
wherein said derivative is prepared by reacting a succinimide-acid
comprising the reaction product of a hydrocarbyl-substituted
succinic acylating agent and an amino acid represented by the
formula: ##STR5##
wherein R is an alkyl group, having from 1 to 12 carbon atoms or an
aryl group with at least one member selected from the group
consisting of polyhydroxy compounds, compounds comprising at least
one primary or secondary amine capable of reacting with said
succinimide-acid, and mixtures thereof.
52. A method of reducing deposits on a lubricated surface, said
method comprising lubricating said surface with the lubricant
composition of claim 51, wherein said succinimide-acid derivative
is present in an amount sufficient to reduce the amount of deposits
on said lubricated surface, as compared to the amount of deposits
on said surface subjected to the same operating conditions and
lubricated with the same lubricant composition except that the
composition is devoid of said succinimide-acid derivative.
53. The method of claim 52 wherein the hydrocarbyl-substituted
succinic acylating agent comprises a polyolefin-substituted
succinic acylating agent.
54. The method of claim 52 wherein the polyolefin-substituted
succinic acylating agent has a number average molecular weight of
from 500 to 7000.
55. The method of claim 54 wherein the polyolefin-substituted
succinic acylating agent has a number average molecular weight of
from 800 to 3000.
56. The method of claim 53 wherein the polyolefin-substituted
succinic acylating agent comprises a polyisobutenyl-substituted
succinic anhydride.
57. The method of claim 52 wherein the hydrocarbyl-substituted
succinic acylating agent comprises an olefin copolymer grafted with
maleic anhydride.
58. The method of claim 57 wherein the olefin copolymer has a
number average molecular weight of from 1000 to 20,000.
59. The method of claim 52 wherein the succinimide-acid derivative
is prepared by reacting a succinimide-acid compound and a compound
comprising at least one primary or secondary amine capable of
reacting with said succinimide-acid.
60. The method of claim 59 wherein the amine comprises a
polyethylene polyamine selected from the group consisting of
diethylene triamine, triethylene tetramine, tetraethylene
pentamine, pentaethylene hexamine, heavy polyamines and mixtures
thereof.
61. The method of claim 59 wherein the amine comprises at least one
hydroxyamine selected from the group consisting of
aminoethylethanolamine, aminopropyl diethanolamine,
3-amino-1,2-propanediol, tris(hydroxymethyl)aminomethane,
2-amino-1,3-propanediol, ethanolamine, diethanolamine and partially
propoxylated hexamethylene diamine.
62. The method of claim 59 wherein the amine comprises at least one
member selected from the group consisting of
N-arylphenylenediamines, aminothiazoles, aminocarbazoles,
aminoindoles, aminopyrroles, amino-indazolinones,
aminomercaptotriazoles, aminoperimidines, aminoalkyl imidazoles and
aminoalkyl morpholines.
63. The method of claim 59 wherein the amine comprises
aminoguanidine.
64. The method of claim 59 wherein the amine comprises an amine
dispersant.
65. The method of claim 52 wherein the succinimide-acid derivative
is prepared by reacting a succinimide-acid compound and a
polyhydroxy compound.
66. The method of claim 65 wherein the polyhydroxy compound
comprises a fully-alkoxylated amine.
67. The method of claim 66 wherein the alkoxylated amine comprises
at least one member selected from the group consisting of
propoxylated hexamethylene diamine, propoxylated triethylene
tetramine, tetrakis(2-hydroxypropyl)ethylenediamine and
triethanolamine.
68. The method of claim 65 wherein the polyhydroxy compound
comprises a polyol.
69. The method of claim 68 wherein the polyol comprises at least
one member selected from the group consisting of glycerol,
sorbitol, pentaerythritol, mannitol and polyalkylene glycols.
70. The method of claim 52 wherein said lubricated surface is in an
internal combustion engine.
71. The method of claim 52 wherein said lubricated surface is in an
automotive drivetrain.
72. The method of claim 52 wherein said lubricated surface is an
automatic transmission friction plate.
73. A fuel composition comprising a hydrocarbonaceous fuel and from
about 0.1 to 10 wt. %, based on the total weight of the fuel
composition, of a succinimide-acid derivative, wherein said
derivative is prepared by reacting a succinimide-acid comprising
the reaction product of a hydrocarbyl-substituted succinic
acylating agent and an amino acid represented by the formula:
##STR6##
wherein R is an alkyl group, having from 1 to 12 carbon atoms or an
aryl group with at least one member selected from the group
consisting of polyhydroxy compounds, compounds comprising at least
one primary or secondary amine capable of reacting with said
succinimide-acid, and mixtures thereof.
74. A method of reducing deposits in the fuel system of an internal
combustion engine, said method comprising using as the fuel for
said internal combustion engine the fuel composition of claim 53
wherein said succinimide-acid derivative is present in the fuel in
an amount sufficient to reduce the deposits in the fuel system, as
compared to the amount of deposits in said fuel system operated in
the same manner and using the same fuel composition except that
said fuel composition is devoid of said succinimide-acid
derivative.
75. The method of claim 74 wherein the hydrocarbyl-substituted
succinic acylating agent comprises a polyolefin-substituted
succinic acylating agent.
76. The method of claim 75 wherein the polyolefin-substituted
succinic acylating agent has a number average molecular weight of
from 500 to 3000.
77. The method of claim 76 wherein the polyolefin-substituted
succinic acylating agent has a number average molecular weight of
from 800 to 2100.
78. The method of claim 75 wherein the polyolefin-substituted
succinic acylating agent comprises at least one member selected
from the group consisting of polyisobutenyl-substituted succinic
anhydride and polypropenyl-substituted succinic anhydride.
79. The method of claim 74 wherein the amine comprises a polyamine
having at least one primary or secondary amino group and at least
one tertiary amino group in the molecule.
80. The method of claim 79 wherein the amine comprises at least one
member selected from the group consisting of
N,N,N",N"-tetraalkyldialkylenetriamines,
N,N,N',N"-tetraalkyltrialkylenetetramines,
N,N,N',N",N'"-pentaalkyltrialkylenetetramines, and
tris(dialkylaminoalkyl)aminoalkylmethanes, wherein the alkyl groups
arc the same or different and contain no more than about 12 carbon
atoms each.
81. The method of claim 80 wherein the amine comprises at least one
member selected from the group consisting of
dimethylaminopropylamine and N-methyl piperazine.
82. The method of claim 74 wherein the amine comprises a
polyethylene polyamine selected from the group consisting of
diethylene triamine, triethylene tetramine, tetraethylene
pentamine, pentaethylene hexamine, heavy polyamines and mixtures
thereof.
Description
TECHNICAL FIELD
The present invention is directed to novel succinimide-acid
compounds prepared by reaction of hydrocarbyl-substituted succinic
acylating agents with amino acids, as well as derivatives thereof
useful as lubricity additives, lubricant dispersants, friction
modifiers, liquid hydrocarbonaceous fuel detergents, antioxidants
and alkali and/or alkaline-earth metal detergents.
BACKGROUND OF THE INVENTION
Hydrocarbyl-substituted succinic anhydride derivatives are widely
used as fuel and lubricant additives. The hydrocarbyl-substituted
succinic anhydride derivatives are typically prepared by reacting a
hydrocarbyl-substituted succinic acylating agent with a polyamine
to form a succinimide.
For example, hydrocarbyl-substituted succinic anhydrides and
derivatives thereof prepared by the thermal reaction of a
polyolefin and maleic anhydride, are described, for example in U.S.
Pat. Nos. 3,361,673 and 3,676,089. Alternatively,
hydrocarbyl-substituted succinic anhydrides can be prepared by the
reaction of chlorinated polyolefins with maleic anhydride, are
described, for example, in U.S. Pat. No. 3,172,892. Additional
examples of hydrocarbyl-substituted succinic anhydrides and
derivatives thereof can be found, for example, in U.S. Pat. Nos.
4,234,435; 4,997,456; 5,393,309 and 5,620,486.
U.S. Pat. Nos. 4,218,328; 4,655,949; and 4,834,892 disclose
lubricating oil additives comprising metal salts of
amino-acids.
None of these patents teach the succinimide-acids, or the
derivatives thereof, of the present invention.
SUMMARY OF THE INVENTION
The succinimide-acid compounds of the present invention are
prepared by reacting amino acids with a hydrocarbyl-substituted
succinic acylating agent. The amino moiety of the amino acid
undergoes reaction with the succinic acylating agent resulting in a
succinimide moiety. This succinimide contains a pendant carboxylic
acid moiety. The pendant carboxylic acid moiety can be utilized by
reaction with various compounds including amines, alkoxylated
amines and polyols to prepare products useful as dispersants,
lubricity additives, friction modifiers, fuel detergents,
antioxidants and alkali and/or alkaline-earth metal detergents.
DETAILED DESCRIPTION OF THE INVENTION
The Succinimide-Acid Compound
The succinimide-acid compounds of the present invention are
prepared by reacting an amino acid with a hydrocarbyl succinic
acylating agent in a reaction media. Suitable reaction media
include, but are not limited to, organic solvents, such as toluene,
or process oil. Water is a by-product of this reaction. The use of
toluene allows for azeotropic removal of water.
The hydrocarbyl-substituted succinic acylating agents include the
hydrocarbyl-substituted succinic acids, the hydrocarbyl-substituted
succinic anhydrides, the hydrocarbyl-substituted succinic acid
halides (especially the acid fluorides and acid chlorides), and the
esters of the hydrocarbyl-substituted succinic acids and lower
alcohols (e.g., those containing up to 7 carbon atoms), that is,
hydrocarbyl-substituted compounds which can function as carboxylic
acylating agents. Of these compounds, the hydrocarbyl-substituted
succinic acids and the hydrocarbyl-substituted succinic anhydrides
and mixtures of such acids and anhydrides are generally preferred,
the hydrocarbyl-substituted succinic anhydrides being particularly
preferred.
The acylating agent for producing the hydrocarbyl substituted
acylating agent is preferably made by reacting a polyolefin of
appropriate molecular weight (with or without chlorine) with maleic
anhydride. However, similar carboxylic reactants can be employed
such as maleic acid, fumaric acid, malic acid, tartaric acid,
itaconic acid, itaconic anhydride, citraconic acid, citraconic
anhydride, mesaconic acid, ethylmaleic anhydride, dimethylmaleic
anhydride, ethylmaleic acid, dimethylmaleic acid, hexylmaleic acid,
and the like, including the corresponding acid halides and lower
aliphatic esters.
The hydrocarbyl-substituted succinic anhydrides are typically
prepared by heating a mixture of maleic anhydride and an aliphatic
olefin at a temperature of about 175-275.degree. C. The molecular
weight of the olefin can vary widely depending upon the intended
use of the substituted succinic anhydrides. Typically, the
substituted succinic anhydrides will have a hydrocarbyl group of
from 8-500 carbon atoms. Friction modifiers, lubricity additives,
antioxidants and fuel detergents generally have a hydrocarbyl group
of about 8-100 carbon atoms, while substituted succinic anhydrides
used to make lubricating oil dispersants will typically have a
hydrocarbyl group of about 40-500 carbon atoms. With the very high
molecular weight substituted succinic anhydrides, it is more
accurate to refer to number average molecular weight (Mn) since the
olefins used to make these substituted succinic anhydrides are a
mixture of different molecular weight components resulting from the
polymerization of low molecular weight olefin monomers such as
ethylene, propylene and isobutylene.
The low molecular weight alkyl-substituents typically contain from
8 to 100 carbon atoms, preferably from 12 to 30 carbon atoms, more
preferably 16 to 26 carbon atoms. The low molecular weight alkyl
substituents include alpha-olefins having single carbon number
fraction between C9 and C30 or a mixture of carbon number fractions
between C9 and C30. The alpha-olefins may be isomerized to produce
an olefin containing an internal double bond, which may be used for
alkylation of the hydroxyaromatic compound. Also useful as the low
molecular weight alkyl substituents are oligomers of 1-olefins.
Examples of such compounds include tridecylsuccinic acid,
pentadecylsuccinic acid, tetradecenylsuccinic acid,
hexadecenylsuccinic acid, dodecylsuccinic acid, tetradecylsuccinic
acid, hexadecylsuccinic acid, octadecenylsuccinic acid,
tetrapropylene-substituted succinic acid, docosenylsuccinic acid
and mixtures thereof. Preferred acylating agents are alkyl and/or
alkenyl succinic anhydrides in which the alkyl or alkenyl group is
substantially straight chain in configuration and contains 12 to 30
carbon atoms, and more preferably an average of about 16 to about
26 carbon atoms. An especially preferred acylating agent of this
type is octadecenylsuccinic acid or anhydride.
Still another preferred hydrocarbyl-substituted acylating agent is
an alkyl- or alkenylsuccinic acid or anhydride in which the alkyl
or alkenyl group is bifurcated on the beta-carbon atom and is
composed of two substantially linear chains. Preferred alkyl groups
of this type may be represented by the formula ##STR1##
where n is an integer in the range of 2 to 10. A preferred group of
such bifurcated alkenyl groups may be represented by the formula
##STR2##
where n is an integer in the range of 2 to 10. It will be
understood and appreciated that the double bond in such alkenyl
group may be isomerized to different positions from that depicted
(which is the preferred position) by treating the alkenylsuccinic
acid or anhydride with an isomerization catalyst such as silica
gel, a trialkylborane, or the like. Such alkyl- and alkenyl
substituted succinic acids and anhydrides can be formed from
dimerized 1-olefins such as by dimerizing 1-hexene, 1-heptene,
1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene,
1-tetradecene, 4-methyl-1-pentene, 6-methyl-1-heptene,
5-ethyl-1-decene, or 3,5,5-trimethyl-1-undecene with an aluminum
alkyl dimerization catalyst according to known procedures. See for
example Ziegler et al, Ann. 629, 121-166 (1960) all disclosure of
which is incorporated herein by reference. The resultant dimerized
olefin (sometimes referred to as a vinylidene olefin) is then used
to alkylate maleic anhydride or an ester of maleic acid, etc., to
form the alkenyl-substituted succinic acid compound by the "ene"
reaction. See in this connection Hoffman, Angew. Chem., Int. Ed.
(English), 8, 556-577 (1969); Snider, J. Org. Chem., 39, 255
(1974); and Keung et al, J. Chem. Educ., 49. 97-100 (1972), all
disclosures of which are incorporated herein by reference. As is
well known, the "ene" reaction may be facilitated by the use of a
catalyst such as aluminum trichloride, alkyl aluminum
sesquichloride or the like. To form the bifurcated alkyl
substituent, the bifurcated alkenyl group of the resultant
alkenyl-substituted succinic acid compound may be hydrogenated to
saturate the double bond.
Similarly suitable alkyl- or alkenylsuccinic acids or anhydrides in
which the alkyl or alkenyl group is bifurcated on the beta-carbon
atom into two branches can be formed in analogous fashion using
co-dimerized 1-olefin such as by co-dimerizing 1-butene and
1-octene, 1-hexene and 1-decene, 1-pentene and 1-dodecene,
4-methyl-1-pentene and 1-tetradecene, 1-octene and 1-decene,
1-nonene and 1-decene, 1-decene and 1-dodecene, 1-dodecene and
1-tetradecene, 2,7-dimethyl-1-octene and 1-decene,
2,7-dimethyl-1-octene and 1-dodecene, 1-tetradecene and
1-pentadecene, etc., using a co-dimerization catalyst such as an
aluminum alkyl. Such co-dimerized olefins are then used in the
"ene" reaction in the same manner as described above. Hydrogenation
of the alkenyl succinic acid compound (anhydride, ester, etc.)
yields the corresponding bifurcated alkyl succinic acid
compound.
The mole ratio of maleic anhydride to olefin can vary widely. It
may vary, for example, from 5:1 to 1:5, a more preferred range is
3:1 to 1:3. With the high molecular weight olefins such as
polyisobutylene having a number average molecular weight of 500 to
7000, preferably 800 to 3000 or higher and the
ethylene-alpha-olefin copolymers, the maleic anhydride is
preferably used in stoichiometric excess, e.g. 1.1-5 moles maleic
anhydride per mole of olefin. The unreacted maleic anhydride can be
vaporized from the resultant reaction mixture.
With the lower molecular weight olefins, e.g. Mn of 100-350, either
reactant can be used in excess or they can be reacted in a 1:1 mole
ratio. Typically an excess of olefin is used, e.g. 1.1-3 moles of
olefin per mole maleic anhydride.
The hydrocarbyl-substituted succinic anhydrides of the present
invention include polyalkyl or polyalkenyl succinic anhydrides
prepared by the reaction of maleic anhydride with the desired
polyolefin or chlorinated polyolefin, under reaction conditions
well known in the art. For example, such succinic anhydrides may be
prepared by the thermal reaction of a polyolefin and maleic
anhydride, as described, for example in U.S. Pat. Nos. 3,361,673
and 3,676,089 and European Patent 0623631 B 1. Alternatively, the
substituted succinic anhydrides can be prepared by the reaction of
chlorinated polyolefins with maleic anhydride, as described, for
example, in U.S. Pat. No. 3,172,892. A further discussion of
hydrocarbyl-substituted succinic anhydrides can be found, for
example, in U.S. Pat. Nos. 4,234,435; 5,620,486 and 5,393,309.
Typically, these hydrocarbyl-substituents will contain from 40 to
500 carbon atoms.
Polyalkenyl succinic anhydrides may be converted to polyalkyl
succinic anhydrides by using conventional reducing conditions such
as catalytic hydrogenation. For catalytic hydrogenation, a
preferred catalyst is palladium on carbon. Likewise, polyalkenyl
succinimides may be converted to polyalkyl succinimides using
similar reducing conditions.
The polyalkyl or polyalkenyl substituent on the succinic anhydrides
employed in the invention is generally derived from polyolefins
which are polymers or copolymers of mono-olefins, particularly
1-mono-olefins, such as ethylene, propylene and butylene.
Preferably, the mono-olefin employed will have 2 to about 24 carbon
atoms, and more preferably, about 3 to 12 carbon atoms. More
preferred mono-olefins include propylene, butylene, particularly
isobutylene, 1-octene and 1-decene. Polyolefins prepared from such
mono-olefins include polypropylene, polybutene, polyisobutene, and
the polyalphaolefins produced from 1-octene and 1-decene.
A particularly preferred hydrocarbyl substituent is one derived
from polyisobutene. Suitable polyisobutenes for use in preparing
the succinimide-acids of the present invention include those
polyisobutenes that comprise at least about 20% of the more
reactive methylvinylidene isomer, preferably at least 50% and more
preferably at least 70%. Suitable polyisobutenes include those
prepared using BF.sub.3 catalysts. The preparation of such
polyisobutenes in which the methylvinylidene isomer comprises a
high percentage of the total composition is described in U.S. Pat.
Nos. 4,152,499 and 4,605,808.
As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl
group" is used in its ordinary sense, which is well-known to those
skilled in the art. Specifically, it refers to a group having a
carbon atom directly attached to the remainder of the molecule and
having predominantly hydrocarbon character. Examples of hydrocarbyl
groups include:
(1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or
alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents,
and aromatic-, aliphatic-, and alicyclic-substituted aromatic
substituents, as well as cyclic substituents wherein the ring is
completed through another portion of the molecule (e.g., two
substituents together form an alicyclic radical);
(2) substituted hydrocarbon substituents, that is, substituents
containing non-hydrocarbon groups which, in the context of this
invention, do not alter the predominantly hydrocarbon substituent
(e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,
mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
(3) hetero substituents, that is, substituents which, while having
a predominantly hydrocarbon character, in the context of this
invention, contain other than carbon in a ring or chain otherwise
composed of carbon atoms. Heteroatoms include sulfur, oxygen,
nitrogen, and encompass substituents such as pyridyl, furyl,
thienyl and imidazolyl. In general, no more than two, preferably no
more than one, non-hydrocarbon substituent will be present for
every ten carbon atoms in the hydrocarbyl group; typically, there
will be no nonhydrocarbon substituents in the hydrocarbyl
group.
For purposes of the present invention, the term
hydrocarbyl-substituted succinic anhydrides includes olefin
copolymers grafted with maleic anhydride. Suitable anhydride
grafted olefin copolymers are well known in the art, for example,
U.S. Pat. No. 4,863,623. Preferred as the olefin copolymer
substrate are copolymers of ethylene and one or more C.sub.3 to
C.sub.23 alpha-olefins. Copolymers of ethylene and propylene are
most preferred. Other alpha-olefins suitable for use in place of
propylene to form the copolymer or to be used in combination with
ethylene and propylene to form a terpolymer include 1-butene,
1-pentene, 1-hexene, 1-octene and styrene;
.alpha.,.omega.-diolefins such as 1,5-hexadiene, 1,6-heptadiene,
1,7-octadiene; branched chain alpha-olefins such as
4-methylbutene-1, 5-methylpentene-1 and 6-methylheptene-1; and
mixtures thereof.
More complex polymer substrates, often designated as interpolymers,
may be prepared using a third component. The third component
generally used to prepare an interpolymer substrate is a polyene
monomer selected from non-conjugated dienes and trienes. The
non-conjugated diene component is one having from 5 to 14 carbon
atoms in the chain. Preferably, the diene monomer is characterized
by the presence of a vinyl group in its structure and can include
cyclic and bicyclo compounds. Representative dienes include
1,4-hexadiene, 1,4-cyclohexadiene, dicyclopentadiene,
5-ethylidene-2-norbornene, 5-methylene-2-norborene, 1,5-heptadiene,
and 1,6-octadiene. A mixture of more than one diene can be used in
the preparation of the interpolymer. A preferred non-conjugated
diene for preparing a terpolymer or interpolymer substrate is
1,4-hexadiene.
The triene component will have at least two non-conjugated double
bonds, and up to about 30 carbon atoms in the chain. Typical
trienes useful in preparing the interpolymer of the invention are
1-isopropylidene-3.alpha.,4,7,7.alpha.-tetrahydroindene,
1-isopropylidenedicyclopentadiene, dihydro-isodicyclopentadiene,
and
2-(2-methylene-4-methyl-3-pentenyl)[2.2.1]bicyclo-5-heptene.
Ethylene-propylene or higher alpha-olefin copolymers typically
comprise from about 15 to 80 mole percent ethylene and from about
85 to 20 mole percent C.sub.3 to C.sub.23 alpha-olefin with the
preferred mole ratios being from about 35 to 75 mole percent
ethylene and from about 65 to 25 mole percent of a C.sub.3 to
C.sub.23 alpha-olefin, with the more preferred proportions being
from 50 to 70 mole percent ethylene and 50 to 30 mole percent
C.sub.3 to C.sub.23 alpha-olefin, and the most preferred
proportions being from 55 to 65 mole percent ethylene and 45 to 35
mole percent C.sub.3 to C.sub.23 alpha-olefin.
Terpolymer variations of the foregoing polymers may contain from
about 0.1 to 10 mole percent of a non-conjugated diene or
triene.
The polymer substrate, that is the ethylene copolymer or
terpolymer, is an oil-soluble, linear or branched polymer having a
number average molecular weight from about 1000 to 20,000 as
determined by gel permeation chromatography and universal
calibration standardization, with a preferred number average
molecular weight range of 6,000 to 10,000.
The terms polymer and copolymer are used generically to encompass
ethylene copolymers, terpolymers or interpolymers. These materials
may contain minor amounts of other olefinic monomers so long as the
basic characteristics of the ethylene copolymers are not materially
changed.
The polymerization reaction used to form the ethylene-olefin
copolymer substrate is generally carried out in the presence of a
conventional Ziegler-Natta or metallocene catalyst system. The
polymerization medium can include solution, slurry, or gas phase
processes, as known to those skilled in the art. When solution
polymerization is employed, the solvent may be any suitable inert
hydrocarbon solvent that is liquid under reaction conditions for
polymerization of alpha-olefins; examples of satisfactory
hydrocarbon solvents include straight chain paraffins having from 5
to 8 carbon atoms, with hexane being preferred. Aromatic
hydrocarbons, preferably aromatic hydrocarbons having a single
benzene nucleus, such as benzene and toluene; and saturated cyclic
hydrocarbons having boiling point ranges approximating those of the
straight chain paraffinic hydrocarbons and aromatic hydrocarbons
described above, are particularly suitable. The solvent selected
may be a mixture of one or more of the foregoing hydrocarbons. When
slurry polymerization is employed, the liquid phase for
polymerization is preferably liquid propylene. It is desirable that
the polymerization medium be free of substances that will interfere
with the catalyst components.
The grafting reaction to form the maleic anhydride grafted olefin
copolymers is generally carried out with the aid of a free-radical
initiator either in solution or in bulk, as in an extruder or
intensive mixing device. When the polymerization is carried out in
hexane solution, it is economically convenient to carry out the
grafting reaction as described in U.S. Pat. Nos. 4,340,689,
4,670,515 and 4,948,842. The resulting polymer is characterized by
having succinic anhydride functionality randomly within its
structure.
In the bulk process for forming the grafted olefin copolymers, the
olefin copolymer is fed to rubber or plastic processing equipment
such as an extruder, intensive mixer or masticator, heated to a
temperature of 150.degree. to 400.degree. C. and the maleic
anhydride and free-radical initiator are separately co-fed to the
molten polymer to effect grafting. The reaction is carried out
optionally with mixing conditions to effect shearing and grafting
of the ethylene copolymers according to U.S. Pat. No. 5,075,383.
The processing equipment is generally purged with nitrogen to
prevent oxidation of the polymer and to aid in venting unreacted
reagents and byproducts of the grafting reaction. The residence
time in the processing equipment is sufficient to provide for the
desired degree of functionalization and to allow for purification
of the functionalized copolymer via venting. Mineral or synthetic
lubricating oil may optionally be added to the processing equipment
after the venting stage to dissolve the functionalized
copolymer.
The free-radical initiators which may be used to graft the maleic
anhydride to the polymer backbone include peroxides,
hydroperoxides, peresters, and azo compounds, preferably those
which have a boiling point greater than 100.degree. C. and
decompose thermally within the grafting temperature range to
provide free radicals. Representatives of these free-radical
initiators are azobutyronitrile, dicumyl peroxide,
2,5-dimethylhexane-2,5-bis-tertiarybutyl peroxide and
2,5-dimethyl-hex-3-yne-2,5-bis-tertiary-butyl peroxide. The
initiator is typically used in an amount of between about 0.005%
and about 1% by weight based on the weight of the reaction
mixture.
Other methods known in the art for effecting reaction of
ethylene-olefin copolymers with maleic anhydride, such as
halogenation reactions, thermal or "ene" reactions or mixtures
thereof, can be used instead of the free-radical grafting process.
Such reactions are conveniently carried out in mineral oil or bulk
by methods known in the art. For example, heating the reactants at
temperatures of 250 to 400.degree. C. under an inert atmosphere to
avoid the generation of free radicals and oxidation byproducts.
"Ene" reactions are a preferred method of grafting when the
ethylene-olefin copolymer contains unsaturation. Depending upon the
amount of anhydride functionality desired, it may be necessary to
follow or proceed the "ene" or thermal graft reaction with a free
radical graft reaction.
The amino acids used in the present invention can be represented by
the following formula: ##STR3##
wherein R is an alkyl group, having from 1 to 12 carbon atoms, or
an aryl group.
Suitable amino acids include alpha-omega amino acids such as
glycine, beta-alanine, gamma-aminobutyric acid, 6-aminocaproic
acid, 7-aminoheptanoic acid, aminocaprylic acid, 11-aminoundecanoic
acid and 12-aminododecanic acid
Suitable aromatic amino acids include those compounds wherein R
comprises benzene, naphthalene and benzophenone. Representative
examples of aromatic amino acids useful in the present invention
include 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic
acid, 4-(aminomethyl) benzoic acid, 2-amino-3-methylbenzoic acid,
2-amino-5-methylbenzoic acid, 2-amino-6-methylbenzoic acid,
3-amino-2-methylbenzoic acid, 3-amino-4-methylbenzoic acid,
4-amino-2-methylbenzoic acid, 6-aminonicotinic acid,
3-amino-2-naphthoic acid, 2-aminobenzophenone-2'-carboxylic acid
and 2-(2aminobenzoyl)benzoic acid.
The molar ratio of anhydride to amino acid ranges from 1:10 to 1:1,
preferably the molar ratio of anhydride to amino acid is 1:1.
The succinimide-acid compounds useful in the present invention are
prepared by combining the hydrocarbyl-substituted succinic
acylating agent and at least one amino acid with a reaction media
in a suitable reaction vessel and reacting at a temperature and for
a time sufficient to form a succinimide. These reaction conditions
are readily determinable by a person skilled in the art. When the
reaction media used is process oil, the reaction mixture is
typically heated to between 120 and 180.degree. C. under nitrogen.
The reaction generally requires 2 to 5 hours for complete removal
of water and formation of the succinimide product. When toluene (or
other organic solvent) is used as the reaction media, the reflux
temperature of the water/toluene (solvent) azeotrope determines the
reaction temperature.
Representative examples of suitable preparation methods for the
succinimide-acids are as follows:
Example: Preparation of SAcid-2
A 2 L round bottom flask equipped with overhead stirrer, condenser,
and Dean-Stark trap was charged with 590 g of an alkenyl succinic
anhydride (Acid #0.35 meq KOH/g), 26.7 g of 6-amino caproic acid
and 300 g of toluene. The reaction mixture was heated at reflux.
After 4 hours 3.2 mL of water was collected. FTIR indicated that
succinimide was formed. The reaction mixture was filtered and
concentrated in vacuo to afford 632 g of product.
Example: Preparation of SAcid-3
A 3 L resin kettle equipped with overhead stirrer, Dean Stark trap,
condenser, and thermometer under a nitrogen atmosphere was charged
with 956 g of an alkenyl succinic anhydride (Acid #0.35 meq KOH/g),
43.3 g of 6-amino caproic acid and 514 g of process oil. The
mixture was heated with stirring under nitrogen to 140.degree. C.
over 1 hour. The reaction temperature was then raised over 1 hour
to 160.degree. C. and held at this temperature for 3 hours. FTIR
indicated that succinimide was formed. The reaction mixture was
cooled and filtered to afford 1483 g of product.
The molar ratio of anhydride to amino acid used in preparing the
succinimide-acid compounds of Table I was approximately 1:1.
TABLE I Synthesized Succinimide-acid (SAcid) compounds: Sample
Anhydride Acid Reaction Media SAcid-1 C.sub.16-18 ASA.sup.1 6-amino
caproic acid Toluene SAcid-2 2100 PIBSA.sup.2 6-amino caproic acid
Toluene SAcid-3 2100 PIBSA 6-amino caproic acid Process Oil SAcid-4
900 PIBSA.sup.3 6-amino caproic acid Toluene SAcid-5 2100 PIBSA
4-amino butyric acid Process Oil SAcid-6 2100 PIBSA 11-amino
undecanoic acid Process Oil SAcid-7 2100 PIBSA gamma-amino butyric
acid Process Oil SAcid-8 C.sub.16-18 ASA 11-amino undecanoic acid
Process Oil SAcid-9 2100 PIBSA 4-aminobenzoic acid Process Oil
SAcid-10 1300 PIBSA.sup.4 6-aminocaproic acid Process Oil .sup.1
C16-18 alkenyl succinic anhydride .sup.2 polyisobutenyl succinic
anhydride derived from polyisobutene having a number average
molecular weight of approximately 2100. .sup.3 polyisobutenyl
succinic anhydride derived from polyisobutene having a number
average molecular weight of approximately 900. .sup.4
polyisobutenyl succinic anhydride derived from polyisobutene having
a number average molecular weight of approximately 1300.
The succinimide-acids of the present invention may be reacted with
additional compounds or polymers to produce products suitable for
numerous applications. Suitable reactants include those capable of
reacting with the acid group of the succinimide-acid, such as
compounds, oligomers and polymers containing amine and/or hydroxy
functionality to form succinimide-amides, succinimide-esters and
mixtures thereof.
Preparation of Succinimide-Acid Derivatives
To prepare succinimide-acid derivatives, the succinimide-acid
compound can reacted with a compound containing at least one
primary or secondary amine capable of reacting with said
succinimide-acid to form the succinimide-amide or a hydroxy
containing compound to form an ester. Mixtures of
succinimide-amides and succinimide-esters may be formed by reaction
of the succinimide-acid compound with a hydroxyamine compound
containing at least one primary or secondary amine capable of
reacting with said succinimide-acid and containing at least one
hydroxy group capable of reacting with said succinimide-acid.
Reaction of the pendant carboxylic acid moiety of the
succinimide-acid compound with the amine results in the formation
of an amide bond. The reaction is conducted at a temperature and
for a time sufficient to form the succinimide-amide reaction
product. These reaction conditions can readily be determined by one
skilled in the art. Typically, the reaction is conducted in a
suitable reaction media such as an organic solvent, for example,
toluene, or process oil. The reaction is typically conducted at a
temperature of from 110 to 180.degree. C. for 2 to 10 hours.
The reactants are preferably used in amounts so as to provide a
ratio of acid groups on the succinimide-acid compound to polyamine
in the range of from n:1 to 1:1 where n is the number of reactive
nitrogen atoms (i.e., unhindered primary and secondary amines
capable of reacting with the acid groups of the succinimide-acid)
within the polyamine.
The preferred amines are polyamines and hydroxyamines. Examples of
polyamines that may be used include, but are not limited to,
aminoguanidine bicarbonate (AGBC), diethylene triamine (DETA),
triethylene tetramine (TETA), tetraethylene pentamine (TEPA),
pentaethylene hexamine (PEHA) and heavy polyamines. A heavy
polyamine is a mixture of polyalkylenepolyamines comprising small
amounts of lower polyamine oligomers such as TEPA and PEHA but
primarily oligomers with 7 or more nitrogens, 2 or more primary
amines per molecule, and more extensive branching than conventional
polyamine mixtures.
Polyamines that are also suitable in preparing the dispersants of
the present invention include N-arylphenylenediamines, such as
N-phenylphenylenediamines, for example,
N-phenyl-1,4-phenylenediamine, N-phenyl-1,3-phenylendiamine, and
N-phenyl-1,2-phenylenediamine; aminothiazoles such as
aminothiazole, aminobenzothiazole, aminobenzothiadiazole and
aminoalkylthiazole; aminocarbazoles; aminoindoles; aminopyrroles;
amino-indazolinones; aminomercaptotriazoles; aminoperimidines;
aminoalkyl imidazoles, such as 1-(2-aminoethyl) imidazole,
1-(3-aminopropyl) imidazole; and aminoalkyl morpholines, such as
4-(3-aminopropyl) morpholine. These polyamines are described in
more detail in U.S. Pat. Nos. 4,863,623; and 5,075,383. These
polyamines can provide additional benefits, such as anti-wear and
antioxidancy, to the final products.
Additional polyamines useful in forming the succinimide-amides of
the present invention include polyamines having at least one
primary or secondary amino group and at least one tertiary amino
group in the molecule as taught in U.S. Pat. Nos. 5,634,951 and
5,725,612. Examples of suitable polyamines include
N,N,N",N"-tetraalkyldialkylenetriamines (two terminal tertiary
amino groups and one central secondary amino group),
N,N,N',N"-tetraalkyltrialkylenetetramines (one terminal tertiary
amino group, two internal tertiary amino groups and one terminal
primary amino group), N,N,N',N",N'"-pentaalkyltrialkylenetetramines
(one terminal tertiary amino group, two internal tertiary amino
groups and one terminal secondary amino group),
tris(dialkylaminoalkyl)aminoalkylmethanes (three terminal tertiary
amino groups and one terminal primary amino group), and like
compounds, wherein the alkyl groups are the same or different and
typically contain no more than about 12 carbon atoms each, and
which preferably contain from 1 to 4 carbon atoms each. Most
preferably these alkyl groups are methyl and/or ethyl groups.
Preferred polyamine reactants of this type include
dimethylaminopropylamine (DMAPA) and N-methyl piperazine.
Hydroxyamines suitable for use in the present invention include
compound, oligomer or polymer containing at least one primary or
secondary amine capable of reacting with the succinimide-acid to
form a succinimide-amide and also containing at least one hydroxy
group capable of reacting with the succinimide-acid to form a
succinimide-ester. Examples of hydroxyamines suitable for use in
the present invention include aminoethylethanolamine (AEEA),
aminopropyldiethanolamine (APDEA), ethanolamine, diethanolamine
(DEA), partially propoxylated hexamethylene diamine (for example
HMDA-2PO or HMDA-3PO), 3-amino-1,2-propanediol,
tris(hydroxymethyl)aminomethane, and 2-amino-1,3-propanediol. When
hydroxyamines are used, the reaction products of the
succinimide-acid and the hydroxyamine may contain mixtures of
succinimide-amides and succinimide-esters.
Reaction of the pendant carboxylic acid moiety of the
succinimide-acid compound with the polyhydroxy compound results in
the formation of an ester bond. The reaction is conducted at a
temperature and for a time sufficient to form the succinimide-ester
reaction product. Typically, the reaction is conducted in a
suitable reaction media such as an organic solvent, for example,
toluene, or process oil. The reaction is typically conducted at a
temperature of from 110 to 180.degree. C. for 2 to 10 hours.
The reactants are preferably used in amounts so as to provide a
ratio of acid groups on the succinimide-acid compound to
polyhydroxy compound in the range of from n:1 to 1:1 where n is the
number of hydroxyl groups in the polyhydroxy compound. It is
preferred that the molar ratio of succinimide-acid compound to
polyhydroxy compound be between 3:1 and 1:1, more preferably the
molar ratio of succinimide-acid compound to polyhydroxy compound is
2:1.
Examples of alkoxylated amines that may be used include fully
alkoxylated amines, i.e., no primary or secondary amine groups
remain, such as propoxylated hexamethylene diamine (HMDA-4PO),
propoxylated triethylene tetramine (TETA-PO),
tetrakis(2-hydroxypropyl)ethylenediamine (EDA-4PO) and
triethanolamine (TEA).
Suitable polyols include glycerol, sorbitol, pentaerythitol,
mannitol and polyalkylene glycols.
Some contemplated uses of the succinimide-acids, and derivatives
thereof, of the present invention include lubricity additives,
lubricant dispersants, friction modifiers, liquid hydrocarbonaceous
fuel detergents, antioxidants and alkali and/or alkaline-earth
metal detergents. Typically, the usefulness of the reaction
products in the above-identified applications will be determined by
the selection of the hydrocarbyl-substituted succinic acylating
agent, the amino acids, and the amines or polyhydroxy compounds
when used.
Preparation of Dispersant Additives
The succinimide-acid compounds of the present invention may be
utilized to prepare compounds suitable for use as dispersants in
lubricating oil formulations or to increase the molecular weight of
existing amine-based dispersant compounds. The pendant carboxylic
acid moiety of the succinimide-acid compound can undergo reaction
with polyamines, partially alkoxylated polyamines and/or
alkoxylated amines to generate reaction products useful as
dispersants. Reaction of polyamines or partially alkoxylated
polyamines with the succinimide-acid compound results in a
succinimide-amide compound. Reaction of fully alkoxylated amines
with the succinimide-acid compound results in a succinimide-ester
compound. Reaction of an amine dispersant with the succinimide-acid
compound results in a succinimide-amide compound.
When preparing the succinimide-amide and succinimide-ester reaction
products for use as lubricating oil dispersants, it is preferred
that the succinimide-acid compound used is formed from a
hydrocarbyl-substituted succinic acylating agent wherein the
hydrocarbyl group on the substituted succinic acylating agent has a
number average molecular weight of from 100 to 20,000. Preferred
hydrocarbyl-substituted succinic acylating agents for use in
preparing the succinimide-amide reaction products useful as
lubricating oil dispersants include polyalkenyl succinic anhydrides
having a number average molecular weight of from 100 to 7000,
preferably 500 to 3000, and maleic anhydride grafted
ethylene-alpha-olefin copolymers having a number average molecular
weight of from 1000 to 20,000, preferably 6000 to 10,000.
Dispersants in the lubricating oil suspend thermal decomposition
and oxidation products, such as soot and sludge, and reduce or
retard the formation of deposits on lubricated surfaces.
Examples of Succinimide-Amide Dispersants
The succinimide-amide reaction products set forth in Table II were
prepared as follows:
Amines and the succinimide-acid compounds, as set forth in Table
II, were combined with process oil in a suitable reaction vessel
and heated to between 160 and 180.degree. C. under nitrogen. The
reaction generally required 4 to 8 hours for formation of the amide
product. Formation of the succinimide-amide can be confirmed by
FTIR or the total acid number (TAN) of the final product can be
determined to estimate the amount of unreacted acid. The molar
ratio of succinimide-acid compound to amine compound used in
preparing the succinimide-amides is set forth in the Table.
A representative example of a suitable preparation method for the
succinimide-amides is as follows:
Example: Preparation of SAmide-3
A 1000 mL resin kettle equipped with overhead stirrer, Dean Stark
trap, and thermometer was charged with 271 g of Sacid-2, 5.7 g of
tetraethylenepentamine and 74.3 g of process oil. The mixture was
heated to 160.degree. C. with stirring and under a continual
nitrogen purge. The reaction mixture was held at this temperature
for 4 hours. Residual water was removed in vacuo to afford 303.6 g
of product.
TABLE II Succinimide-Amide (SAmide) Reaction Products Ratio Sample
Succinimide-Acid Amine (Sacid:Amine) SAmide-1 SAcid-6 TEPA 1:0.25
SAmide-2 SAcid-1 TEPA 1:0.33 SAmide-3 SAcid-2 TEPA 1:0.33 SAmide-4
SAcid-2 TEPA 1:0.5 SAmide-5 SAcid-6 TEPA 1:0.5 SAmide-6 SAcid-5
TEPA 1:0.5 SAmide-7 SAcid-2 AGBC 1:1 SAmide-8 SAcid-3 APDEA 1:1
SAmide-9 SAcid-6 AEEA 1:1 SAmide-10 SAcid-6 DEA 1:1 SAmide-11
SAcid-7 TEPA 1:0.5 Samide-12 SAcid-9 TEPA 1:0.5
Heavy-duty diesel style lubricant formulations containing the
succinimide-amide reaction products, described above in Table II,
were evaluated in dispersant bench tests, the Spot Dispersancy Test
(SDT) and Soot Thickening Test (STT). The impact on viscometrics
(Kinematic Viscosity at 100.degree. C. (KV100) and Cold Cranking
Simulator (CCS)) of the succinimide-amide reaction products on PCMO
style formulations was also evaluated.
Spot Dispersancy Test
The Spot Dispersancy Test affords a measure of an additive's
ability to disperse sludge. In the Spot Dispersancy Test, a
dispersant candidate is mixed with an amount of Sequence VE sludge
oil and is incubated at 300.degree. F. for 16 hours. The resulting
mixture (3-10 drops) is dropped onto a standard white blotter paper
producing a sludge/oil spot. After 24 hours, the diameter of the
sludge and the oil rings are measured. As dispersancy is the
ability of an oil to keep sludge in suspension, dispersancy in the
Spot Dispersancy Test is reflected by the difference in diameters
of the sludge and oil rings. The sludge ring being nearly as wide
as the oil ring reflects high dispersancy. Multiplying the quotient
of the sludge ring and the oil ring diameters by 100 produces a
rating (SDT Rating). A high numerical rating is indicative of good
dispersance. Table III depicts the Spot Dispersancy Test
performance of several additives of the present invention. All of
the dispersants were added to the sludge oil in an amount of 4 wt.
%.
TABLE III Spot Dispersancy Test Results for succinimide-amides
Sample # Dispersant SDT Rating 1* none 25.6 2* Mannich control 60.4
3 SAmide-3 74.2 4 SAmide-4 75.4 5 SAmide-7 73.5 6 SAmide-8 75.0 7
SAmide-11 73.5 8 Samide-12 71.9
The test procedure is described in Example 1 of U.S. Pat. No.
4,908,145. The Mannich control dispersant afforded a SDT rating of
60.4. These commercial Mannich products exhibit excellent
dispersancy in gasoline engine test performance (Sequence VE and
Sequence IIIE) and excellent diesel engine test performance. A Spot
Dispersant Test Rating above 60, therefore, with 4 wt. % added
dispersant is indicative of good dispersancy. As indicated in Table
III, the additives of this invention would likewise be expected to
afford excellent dispersancy.
Viscosity Index Credit
Additives of this invention, a commercially-available Mannich
dispersant, and a commercially-available succinimide dispersant
were blended into a motor oil formulation containing
metal-sulfonates, zinc dithiophosphate wear inhibitors, sulfur
containing antioxidants, a pour point depressant, and a viscosity
index improver. Additives of the invention and the commercial
Mannich dispersant were of nearly equal activities (approximately
40 wt. %), while the commercial succinimide dispersant had a higher
activity of 65 wt. %.
Table IV details the viscosity index improving credit advantages
exhibited by several dispersants of this invention. For oils
formulated as described above, 4.9 wt. % of the Mannich dispersant
or the succinimide dispersant required 7.5 wt. % of a
commercially-available non-dispersant olefin copolymer viscosity
index improver to meet a viscosity target of 10.0 to 10.6 cSt
(centistokes). On the other hand, the dispersants additives of the
invention required lower amounts (3 to 8 wt. % less) of this same
viscosity index improver to meet or exceed the 100.degree. C.
viscosity target. The dispersants of the present invention
advantageously impart blending versatility by addressing both the
low and high temperature 5W-30 specifications.
Soot Thickening Test (STT) Performance
The ability of the dispersants of this invention to disperse soot
and soot induced oil thickening was measured in a soot thickening
bench test. In this test, the dispersant in a fully formulated
15W-40 lubricant composition is sheared in the presence of carbon
black, a soot mimic. The lubricating compositions for the STT
contain the test dispersant at 6.5 wt. % on an as is basis, as well
as metal-containing sulfonates, zinc dithiophosphate wear
inhibitors, sulfur containing antioxidants, a pour point
depressant, and a viscosity index improver. The viscosity of the
sooted mixture and its fresh oil analog is measured at 100.degree.
C. using a capillary viscometer. The percent viscosity increase is
calculated by comparing the viscosity of the fresh oil and its
counterpart treated with carbon black. Lower percent viscosity
increases are indicative of better soot dispersancy.
Table IV also sets forth the kinematic viscosities and the results
of the cold cranking simulator (CCS) for various passenger car
motor oil (PCMO) lubricating oil formulations. In the examples, 4.9
percent by weight of the dispersants indicated in Table IV were
added to identical lubricating oil formulations containing an SAE
5W-30 mineral oil basestock having the same detergent-inhibitor
package. A commercially-available non-dispersant olefin copolymer
viscosity index improver was added to meet a viscosity target of
10.0 to 10.6 cSt (centistokes). The amount of added viscosity index
improver (VII) is set forth in the Table. A reduction in low
temperature viscosity, as indicated by the Cold Cranking Simulator
test, is indicative of good low temperature properties.
TABLE IV Evaluation of Succinimide-Amide reaction products
Succinimide-Amide Added VII CCS Run Reaction Products (wt. %) KV100
@ -25.degree. C. STT 1 SAmide-1 7.5 11.06 3370 63.0 2 SAmide-3 6.8
10.39 3500 69.4 3 SAmide-4 7.1 10.57 3520 61.76 4 SAmide-7 6.8
10.56 3410 N.A. 5 SAmide-8 7.5 10.88 3340 N.A. 6 SAmide-9 7.5 10.82
3350 N.A. 7 SAmide-12 7.5 11.06 3370 52.3 8* PIBSA/ 7.5 10.85 3410
N.A. APDEA (1:1) 9* Mannich Control 7.5 10.82 3620 N.A. 10*
Succinimide Control 7.5 10.04 3460 N.A. 11* Mixed dispersant --
N.A. NA. 80.2 Control.sup.1 *Comparative Example .sup.1 STT control
utilized a mixture of commercially-available dispersants.
The additives of the present invention impart equivalent or higher
100.degree. C. viscosities to motor oil formulations compared to
the two commercial dispersants by virtue of the advantageous higher
molecular weight of the additives of this invention. More
importantly, the dispersants of this invention impart 100.degree.
C. viscosity lift to finished oils with no adverse effects on low
temperature viscometrics.
The additives of this invention contribute viscosity index credit
to finished oils, reducing the amount of conventional viscosity
index improver required to achieve a desired viscosity target.
Reducing the amount of viscosity index improver in a motor oil can
thus offer both cost and engine cleanliness advantages. Further,
the low CCS viscosities obtained in compositions of the present
invention allows one to formulate lubricating oil compositions
containing less or even no unconventional, i.e., synthetic, oils
such as poly-alpha-olefins, and still meet the performance
requirements set forth for crankcase lubricating oils. The
unexpected ability to formulate lubricating oils according to the
present invention using higher amounts of mineral oil, without a
decrease in performance, results in more formulation flexibility as
well as cost savings.
Examples of Succinimide-Ester Dispersants
The succinimide-ester reaction products set forth in Table V were
prepared as follows:
The alkoxylated amine and succinimide-acid compounds, as set forth
in Table V, were combined with process oil in a suitable reaction
vessel and heated to between 140 and 180.degree. C. under nitrogen.
The reaction generally required 4 to 8 hours for formation of the
esters products. The molar ratio of succinimide-acid compound to
alkoxylated amine used is set forth in the Table.
A representative example of a suitable preparation method for the
succinimide-esters is as follows:
Example: Preparation of SEster-1
A 500 mL resin kettle equipped with overhead stirrer, Dean Stark
trap and thermometer was charged with 182.7 g of SAcid-3, and 6.3 g
of a fully propoxylated triethylene tetraamine (TETA-4PO). The
reaction mixture was heated to 160.degree. C. with stirring under a
continual nitrogen purge. The reaction temperature was then raised
to and held at 180.degree. C. for 3 hours. Residual water was
removed in vacuo to afford 182 g of product.
TABLE V Succinimide-Ester (SEster) Reaction Products Succinimide-
Alkoxylated Ratio Sample Acid Amine (SAcid: alkoylated amine)
SEster-1 SAcid-3 TETA-4PO 1:0.33 SEster-2 SAcid-3 TETA-4PO 1:0.5
SEster-3 SAcid-5 TETA-4PO 1:0.5 SEster-4 SAcid-6 TETA-4PO 1:0.5
SEster-5 SAcid-5 HMDA-4PO 1:0.5 SEster-6 SAcid-3 HMDA-4PO 1:0.5
SEster-7 SAcid-6 HMDA-4PO 1:0.5 SEster-8 SAcid-6 TEA 1:1 SEster-9
SAcid-7 TETA-4PO 1:0.5 SEster-10 SAcid-7 HMDA-4PO 1:0.5 SEster-11
SAcid-9 TETA-4PO 1:0.5
The succinimide-ester reaction products, described above in Table
V, were evaluated in dispersant bench tests, the Spot Dispersancy
Test (SDT) and Soot Thickening Test (STT). Their impact on
viscometrics (Kinematic Viscosity at 100.degree. C. (KV100) and
Cold Cranking Simulator (CCS) of PCMO formulations was also
evaluated. The results are set forth in Table VI.
TABLE VI Evaluation of Succinimide-Ester reaction products
Succinimide-Ester CCS Run Reaction Products SDT KV100 @ -25.degree.
C. STT 1 SEster-1 75.0 10.65 3400 45.1 2 SEster-2 78.8 10.72 3250
36.15 3 SEster-9 74.3 10.72 3410 48.21 4 SEster-4 77.6 10.87 3240
37.75 5 SEster-10 71.4 10.85 3470 N.A. 6 SEster-6 74.3 10.76 3240
75.0 7 SEster-7 74.3 10.78 3310 59.1 8 SEster-8 74.2 10.70 3410
N.A. 9 SEster-11 79.5 10.87 3730 21.7 10* Mannich Control 60.4
10.82 3620 N.A. 11* Succinimide Control N.A. 10.04 3460 N.A. 12*
Mixed dispersant N.A. N.A. N.A. 80.2 *Comparative Examples
Candidates were tested at a treat rate of 4% in the SDT. PCMO
formulation at 2.009% active dispersant and 7.5% VI improver for
KV100 and CCS.
The succinimide-esters of the present invention exhibit superior
dispersant properties (i.e., higher SDT results) compared to the
Mannich control according to the Spot Dispersancy Test.
The succinimide-ester additives of the present invention impart
equivalent or higher 100.degree. C. viscosities to motor oil
formulations compared to the two commercial dispersants by virtue
of the advantageous higher molecular weight of the additives of
this invention. More importantly, the dispersants of this invention
impart 100.degree. C. viscosity lift to finished oils with no
adverse effects on low temperature viscometrics.
The succinimide-ester additives of this invention contribute
viscosity index credit to finished oils, reducing the amount of
conventional viscosity index improver required to achieve a desired
viscosity target. Reducing the amount of viscosity index improver
in a motor oil can thus offer both cost and engine cleanliness
advantages. Further, the low CCS viscosities obtained in
compositions of the present invention allows one to formulate
lubricating oil compositions containing less or even no
unconventional, i.e., synthetic, oils such as poly-alpha-olefins,
and still meet the performance requirements set forth for crankcase
lubricating oils. The unexpected ability to formulate lubricating
oils according to the present invention using higher amounts of
mineral oil, without a decrease in performance, results in more
formulation flexibility as well as cost savings.
Increasing the Molecular Weight of Amine-Based Dispersants
The pendant carboxylic acid moiety of the succinimide-acid compound
can undergo reaction with amine containing dispersants to generate
higher molecular weight lubricating oil dispersants.
Examples of dispersants that may be modified include any amine
dispersants having a reactive (i.e., unhindered primary and/or
secondary) amine group. Suitable dispersants include mono- and
bis-succinimides, Mannich condensation products, hydrocarbyl amines
(such as polybutene amines) and polyether amines. Reaction with the
pendant carboxylic acid moiety of the succinimide-acid compound
with the amine dispersant will result in an amide bond. This new
compound will have a three-dimensional shape and an increased
molecular weight.
The reactants are preferably used in amounts so as to provide a
ratio of acid groups on the succinimide-acid compound to dispersant
in the range of from n:1 to 0.1:1 where n is the number of reactive
nitrogen atoms present in the dispersant.
The modified amine dispersants in the following examples were
prepared as follows:
The amine dispersant and succinimide-acid compounds, as set forth
in Table VII, were combined with process oil in a suitable reaction
vessel and heated to between 160 and 180.degree. C. under nitrogen.
The reaction generally required 4 to 8 hours for formation of the
succinimide-amide products. The molar ratio of succinimide-acid
compound to the amine dispersant is set forth in the Table.
A representative example of a suitable method of preparing the
modified amine dispersants is as follows.
Example: Preparation of MAD-1
A 500 mL resin kettle equipped with overhead stirrer, Dean Stark
trap, and thermometer was charged with 91.4 g of SAcid-3, 77.8 g of
a succinimide dispersant (1.8% N) and 44.3 g of process oil. The
reaction mixture was heated to 160.degree. C. with stirring under a
continual nitrogen purge. The reaction temperature was raised to
and held at 180.degree. C. for 3 hours. Residual water was removed
in vacuo to afford 208.2 g of product.
TABLE VII Modified Amine Dispersants (MAD): Succinimide- Ratio
Sample Acid Amine Dispersant (SAcid:amine dispersant) MAD-1 SAcid-3
Succinimide.sup.1 1:1 MAD-2 SAcid-3 Succinimide.sup.1 1:0.5 MAD-3
SAcid-3 Mannich.sup.2 1:1 MAD-4 SAcid-3 Mannich.sup.2 1:0.5 MAD-5
SAcid-9 Mannich.sup.2 1:0.5 .sup.1 A bis-succinimide derived from
1300 molecular weight polybutene-substituted succinine anhydride
and tetraethylene pentamine .sup.2 A Mannich dispersant comprising
the Mannich condensation reaction product of a 2100 molecular
weight polybutene phenol and tetraethylene pentamine
The succinimide-acid modified amine dispersant, described above in
Table VII, were evaluated in dispersant bench tests, the Spot
Dispersancy Test (SDT) and Soot Thickening Test (STT). The
succinimide-acid modified amine dipsersants were also evaluated for
their impact on viscometrics (Kinematic Viscosity at 100.degree. C.
(KV 100) and Cold Cranking Simulator (CCS)) of PCMO formulations.
All of the PCMO formulations contained 7.5 wt. % of a
commercially-available non-dispersant olefin copolymer viscosity
index improver and approximately 2 wt. % active dispersant. The
results of the evaluation are set forth in Table VIII.
TABLE VIII Evaluation of the Succinimide-acid Modified Amine
Dispersants Run Modified Amine Dispersant KV100 CCS SDT STT 1 MAD-1
10.57 3220 51.5 66.3 2 MAD-3 10.76 3350 75.8 75.3 3 MAD-2 10.85
3280 N.A. 53.5 4 MAD-4 10.67 3280 68.2 81.8 5 MAD-5 11.41 4013 75.8
N.A. 6* Succinimide 10.04 3460 N.A. N.A. 7* Mannich 10.45 3600 66.7
.sup. 80.2.sup.1 *Comparative examples .sup.1 Mixed dispersant
control described in footnote 1 of Table IV.
The succinimide-acids of the present invention allow for the
preparation of significantly higher molecular weight dispersants
(50 to 100% higher) than is available from the conventional
approach of preparing bis-succinimide or Mannich dispersants.
The modified amine dispersants of the present invention impart
higher 100.degree. C. viscosities to motor oil formulations
compared to the two commercial dispersants by virtue of the
advantageous higher molecular weight of the additives of this
invention. More importantly, the dispersants of this invention
impart 100.degree. C. viscosity lift to finished oils with no
adverse effects on low temperature viscometrics.
The additives of this invention contribute viscosity index credit
to finished oils, reducing the amount of conventional viscosity
index improver required to achieve a desired viscosity target.
Reducing the amount of viscosity index improver in a motor oil can
thus offer both cost and engine cleanliness advantages. Further,
the low CCS viscosities obtained in compositions of the present
invention allows one to formulate lubricating oil compositions
containing less or even no unconventional, i.e., synthetic, oils
such as poly-alpha-olefins, and still meet the performance
requirements set forth for crankcase lubricating oils. The
unexpected ability to formulate lubricating oils according to the
present invention using higher amounts of mineral oil, without a
decrease in performance, results in more formulation flexibility as
well as cost savings.
Preparation of Lubricity Additives
Problems associated with fuel lubricity arose in the mid-1960's
when a number of aviation fuel pump failures occurred. After
considerable research, it was realized that advances in the
refining of aviation turbine fuel had resulted in the almost
complete removal of the naturally occurring lubricating components
from the fuel. The removal of these natural lubricants resulted in
the seizure of fuel pump parts. By the mid-1980's, it seemed likely
that a similar problem was imminent in diesel fuel pumps. Fuel
injection pump pressures had been steadily increasing while there
was also a growing concern to reduce the sulfur content of the
diesel fuel. The desire to reduce the sulfur content of the diesel
fuel, in an effort to reduce pollution, required the use of more
rigorous fuel refining processes. It was determined that as
refining processes became more stringent, the naturally occurring
oxygen containing compounds and polyaromatics which contribute to
diesel fuel's inherent lubricity were eliminated. In response to
these developments, a number of effective lubricity additives were
developed for diesel fuels. These additives are now widely used to
enhance the lubricity of highly refined, low sulfur diesel
fuels.
Gasoline fuels are also becoming subject to compositional
constraints, including restrictions on sulfur content, in an effort
to reduce pollutants. The principle concern is the effect of sulfur
on exhaust catalyst life and performance. The lubricity
requirements of gasoline are somewhat lower than for diesel fuel
since the majority of gasoline fuel injection systems inject fuel
upstream of the inlet valves and thus operate at much lower
pressures than diesel fuel pumps. However, as automobile
manufacturers desire to have electrically powered fuel pumps within
the fuel tanks, failure of the pumps can be expensive to repair.
These problems are also likely to increase as injection systems
become more sophisticated and the gasoline fuels become more highly
refined.
Additional pump wear concerns have arisen with the introduction of
vehicles having direct injection gasoline engines since the fuel
pumps for these vehicles operate at significantly higher pressures
than traditional gasoline fuel pumps.
The succinimide-acid compounds of the present invention are useful
as lubricity additives for fuel compositions. These compounds can
also be used to form reaction products useful as non-acidic
lubricity additives for fuels compositions. The pendant carboxylic
acid moiety of the succinimide-acid compound can undergo reaction
with hydroxyamines or polyols to generate reaction products
containing at least one pendant hydroxyl group useful as lubricity
additives for liquid fuels. When preparing compounds for use as
lubricity additives, it is preferred to use succinimide-acid
compounds derived from a low molecular alkyl or alkenyl succinic
acylating agents, preferably C.sub.8 -C.sub.100 alkenyl succinic
anhydrides, more preferably C.sub.12 -C.sub.30 alkenyl succinic
anhydrides and most preferably C.sub.16 -C.sub.26 alkenyl succinic
anhydrides.
Compounds suitable for reaction with the succinimide-acids of the
present invention to form non-acidic lubricity additives are
hydroxyl-group containing reactants capable of reacting with the
succinimide-acid to form a succinimide-ester, a succinimide-amide
or mixtures thereof, and which possess at least one pendant
hydroxyl group after reaction with the succinimide-acid. The
preferred hydroxy-group containing reactants for use in preparing
the non-acidic lubricity additives are hydroxyamines; alkoxylated
amines; polyols and mixtures thereof. Examples of suitable
hydroxyamines include ethanolamine, diethanolamine,
triethanolamine, aminoethylethanolamine, aminopropyldiethanolamine,
3-amino-1,2-propanediol, tris(hydroxymethyl)aminomethane, and
2-amino-1,3-propanediol; representative alkoxylated amines include
ethoxylated and propoxylated amines and polyamines. An example of
these amines includes, for example, 2-(methylamino)ethanol.
Suitable polyols include glycerol, sorbitol, pentaerythitol,
mannitol and polyalkylene glycols. Most preferred is
diethanolamine.
Reaction with the pendant carboxylic acid moiety of the
succinimide-acid compound with the hydroxyamines results in esters,
amides or mixtures thereof. Reaction with the pendant carboxylic
acid moiety of the succinimide-acid compound by the polyols or
tertiary amine alkoxides result in an ester bond. The ratio of acid
groups on the succinimide-acid compound to hydroxy-group containing
reactant ranges from m-1:1 to 1:1, wherein `m` is the number of
hydroxy groups present on the hydroxy-group containing reactant.
When `m` is 1, as in ethanolamine, the ratio of succinimide-acid
compound to hydroxy-group containing reactant is preferably 1:1.
Regardless of the value of `m`, it is preferred that the molar
ratio of succinimide-acid compound to hydroxy-group containing
reactant be 1:1. Preferably, when preparing the non-acidic
lubricity additives, the molar proportions of the succinimide-acid
compound and the hydroxy-group containing reactant are selected
such that at least one pendant hydroxyl group remains after
reaction.
EXAMPLES
Reaction products set forth in Table IX, suitable for use as
lubricity additives, were prepared as follows:
The hydroxyamine and succinimide-acid compounds, set forth in Table
IX, were combined with toluene in a suitable reaction vessel and
heated at the water/toluene azeotrope reflux temperature, under
nitrogen. The reaction generally requires 4 to 8 hours for
formation of the reaction products. The molar ratio of
succinimide-acid compound to the hydroxyamine is set forth in Table
IX.
A representative example of a suitable method of preparing the low
molecular weight succinimide-acid derivatives is as follows.
Example: Preparation of LowMW-1
A 1000 mL round bottom flask equipped with overhead stirrer, Dean
Stark trap, and thermometer was charged with 96.5 g of SAcid-1,
20.9 g of diethanolamine and 190 g of toluene. The reaction mixture
was heated at reflux. After 6 hours 3.2 mL of water was collected.
The reaction mixture was concentrated in vacuo to afford 120 g of
product.
TABLE IX Preparation of low molecular weight non-acidic
succinimide-acid derivatives (lowMW): Succinimide- Ratio Sample
Acid Hydroxyamine (SAcid:alkoylated amine) LowMW-1 SAcid-1 DEA 1:1
LowMW-2 SAcid-8 DEA 1:1 LowMW-3 SAcid-8 AEEA 1:1
The efficacy of the reaction products of Table IX as lubricity
additives was assessed using the Scuffing Load BOCLE
(ball-on-cylinder lubricity evaluator) test (ASTM D 6078-97).
The Scuffing Load BOCLE test allows discrimination and ranking of
fuels of differing lubricity. The Scuffing test simulates the
severe modes of wear failure encountered in fuel pumps and
therefore provides results which are representative of how the fuel
would behave in service. The load at which wear failure occurs is
referred to as the scuffing load and is a measure of the inherent
lubricity of the fuel. The scuffing load is primarily identified by
the size and appearance of the wear scar on the ball, which is
considerably different in appearance to that found under milder
non-scuffing conditions. Fuels giving a high scuffing load on
failure have better lubricating properties than fuels giving a low
scuffing load on failure. All tests were conducted in a Jet A fuel
containing 100 ppm w/w of the reaction products as set forth in the
following Table.
Table X demonstrates the effectiveness of the additives of the
present invention as lubricity additives. Higher Scuffing Load
BOCLE values are indicative of improved lubricity.
TABLE X Evaluation of lubricity properties for low molecular weight
succinimide-acid and derivatives thereof Run Sample BOCLE 1 LowMW-1
2200 2 LowMW-2 2400 3 LowMW-3 2800 4 SAcid-1 2800 5 SAcid-8 1800 6
SAcid-4 2200 7* Clear fuel-no additive 1200 *Comparative
Examples
It is clear, upon examination of the data in Table X, that the fuel
composition containing the additives of the present invention
exhibit improved lubricity as compared to base fuel alone. The
succinimide-acid deriviatives (set forth in Runs 1-3, in addition
to their lubricity benefits, have the added advantage of being
non-acidic.
Preparation of Friction Modifiers
The pendant carboxylic acid moiety of the succinimide-acid compound
can undergo reaction with polyamines, hydroxyamines and
polyhydroxyl containing compounds (polyols) to prepare compounds
useful as friction modifiers. These additives can be useful in
numerous formulations where friction modifiers are required
including automatic transmission fluids, continuously variable
transmission fluids, passenger car motor oils, heavy duty diesel
engine oils, gear oils and medium speed diesel engine oils. When
preparing compounds for use as friction modifiers in lubricating
oil compositions, it is preferred to use succinimide-acid compounds
derived from a low molecular alkyl or alkenyl succinic acylating
agents, preferably C.sub.8 -C.sub.100 alkenyl succinic anhydrides,
more preferably C.sub.12 -C.sub.30 alkenyl succinic anhydrides and
most preferably C.sub.16 -C.sub.26 alkenyl succinic anhydrides.
An example of a polyamine utilized in this disclosure for the
preparation of friction modifiers is aminoguanidine. Reaction of
the pendant carboxylic acid moiety of the succinimide-acid compound
and aminoguanidine results in an amide bond. Preferably, the molar
ratio of aminoguanidine to succinimide-acid is approximately
1:1.
Examples of hydroxyamines that may be used include ethanolamine,
diethanolamine, aminoethylethanolamine, aminopropyldiethanolamine,
3-amino-1,2-propanediol tris(hydroxymethyl)aminomethane, and
2-amino-1,3-propanediol.
Reaction with the pendant carboxylic acid moiety of the
succinimide-acid compound by the amine moiety of the hydroxyamine
results in amides, esters or mixtures thereof.
Examples of polyhydroxyl containing compounds (polyols) include
glycerol, sorbitol, pentaerythritol, triethanolamine and
mannitol.
Reaction with the pendant carboxylic acid moiety of the
succinimide-acid compound by the hydroxyl moiety of the polyol
results in an ester bond. The ratio of acid groups on the
succinimide-acid compound to hydroxyl-group containing reactant
(i.e. hydroxyamine or polyol) ranges from m-1:1 to 1:1, wherein `m`
is the number of hydroxy groups present on the hydroxy-group
containing reactant. When `m` is 1, as in ethanolamine, the ratio
of succinimide-acid compound to hydroxy-group containing reactant
is preferably 1:1. Regardless of the value of `m`, it is preferred
that the molar ratio of succinimide-acid compound to hydroxy-group
containing reactant be 1:1. It is desirable to select the molar
proportions of the succinimide-acid compound and the hydroxy-group
containing reactant are selected such that at least one pendant
hydroxyl group remains after reaction.
Reaction products suitable as friction modifiers were prepared as
follows:
The polyamine, succinimide-acid compound and process oil were
combined and heated to 180.degree. C. under nitrogen. The reaction
generally required 4 to 8 hours for formation of the
succinimide-amide product or succinimide-ester product.
A representative example of a suitable method of preparing the
succinimide-amide friction modifiers is as follows.
Example: Preparation of FM-1
A 1000 mL resin kettle equipped with overhead stirrer, dean stark
trap, and thermometer was charged with 88 g of SAcid-1, 27.2 g of
aminoguanidine bicarbonate and 99.2 g of process oil. The mixture
was heated to 70.degree. C. for 30 minutes. The reaction
temperature was raised to 120.degree. C. for 30 minutes and then
raised to and held at 160.degree. C. for 2 hours. Residual water
was removed in vacuo to afford 188 g of product.
TABLE XI Synthesized Succinimide-amide Friction Modifiers (FM):
Ratio Sample Succinimide-acid Polyamine
(succinimide-acid:polyamine) FM-1 SAcid-1 AGBC 1:1 FM-2 SAcid-1 DEA
1:1 FM-3 SAcid-8 DEA 1:1 FM-4 SAcid-8 AEEA 1:1 FM-5 SAcid2 AGBC
1:1
Aminoguanidine amides have been shown to be excellent silver
lubricity additives in Medium Speed Diesel formulations (see, for
example, U.S. Pat. No. 4,948,523). Current commercially available
aminoguanidine amide is a biphasic oil/paste. The aminoguanidine
amides prepared as described above are clear homogenous oils.
Preparation of Detergent Additives for Liquid Fuels
The pendant carboxylic acid moiety of the succinimide-acid compound
can undergo reaction with polyamines to generate useful gasoline
detergent additives including intake valve deposit control
additives for spark-ignition internal combustion engines including
direct injection gasoline engines as well as detergent additives
for fuels, such as diesel fuel, for use in compression-ignition
engines. When preparing compounds for use as fuel detergents, it is
preferred to use succinimide-acid compounds derived from an
polyalkyl or polyalkenyl succinic acylating agent having a number
average molecular weight of from 500 to 3000, preferably 800 to
2100. Preferred polyalkyl and polyalkenyl groups include
polypropylene and polyisobutylene.
Examples of polyamines suitable for use in preparing
succinimide-amides for use as fuel detergents include those
polyamines known in the art for use in preparing fuel detergents as
taught, for example, in U.S. Pat. Nos. 3,948,619; 5,634,951 and
5,725,612. Preferred amines include 3-dimethylaminopropylamine,
aminoethylethanolamine, aminopropyl diethanolamine, diethylene
triamine, triethylene tetramine, and tetraethylene pentamine.
Reaction with the pendant carboxylic acid moiety of the
succinimide-acid compound by the amine results in an amide bond.
The ratio of succinimide-acid compound to polyamine ranges from n:1
to 1:1 where n is the number of reactive nitrogen atoms (i.e.,
unhindered primary and secondary amines capable of reacting with
the succinimide-acid) within the polyamine. It is preferred that
the molar ratio of succinimide-acid compound to polyamine be
1:1.
A typical method for preparing compounds suitable for use as fuel
detergents from the succinimide-acids of the present invention is
as follows:
The polylamine, succinimide-acid compound and toluene are combined
and heated at the water/toluene azeotrope reflux, under nitrogen.
The reaction generally requires 2 to 10 hours for formation of the
succinimide-amide product. Aromatic 150 can be utilized instead of
toluene in this reaction.
A representative example of a suitable method of preparing the
succinimide-amides suitable for use as fuel detergents is as
follows.
Example: Preparation of FuelDet-1
A 2 L round bottom flask equipped with overhead stirrer, Dean Stark
trap, was charged with 278.4 g of SAcid-4 and 20.4 g of
dimethylaminopropylamine and 300 g of toluene. The mixture was
stirred and heated at reflux. After 6 hours 3.2 mL of water was
collected. The reaction mixture was concentrated in vacuo to afford
261 g of product.
TABLE XII Synthesized Fuel Detergents (FuelDet) Succinimide- Ratio
Sample acid Polyamine (succinimide-acid:polyamine) FuelDet-1
SAcid-4 DMAPA 1:1 FuelDet-2 SAcid-4 TETA 1:0.5
The products of Table XII are expected to be effective detergent
additives for use in fuels for spark-ignition engines, including
direct injection gasoline engines, and compression-ignition
engines.
Preparation of Antioxidants
The pendant carboxylic acid moiety of the succinimide-acid compound
can undergo reaction with polyamines to prepare compounds useful as
antioxidants. These additives can be useful in numerous
formulations where antioxidants are required including
spark-ignition fuels, compression-ignition fuels, automatic
transmission fluids, continuously variable transmission fluids,
passenger car motor oils, heavy duty diesel engine oils, gear oils
and medium speed diesel engine oils. When preparing compounds for
use as antioxidants in lubricating oil and fuel compositions, it is
preferred to use succinimide-acid compounds derived from a low
molecular alkyl or alkenyl succinic acylating agents, preferably
C.sub.8 -C.sub.100 alkenyl succinic anhydrides, more preferably
C.sub.12 -C.sub.30 alkenyl succinic anhydrides and most preferably
C.sub.16 -C.sub.26 alkenyl succinic anhydrides.
Polyamines particularly suitable for the preparation of
antioxidants include N-arylphenylenediamines, such as
N-phenylphenylenediamines, for example,
N-phenyl-1,4-phenylenediamine, N-phenyl-1,3-phenylendiamine, and
N-phenyl-1,2-phenylenediamine; aminothiazoles such as
aminothiazole, aminobenzothiazole, aminobenzothiadiazole and
aminoalkylthiazole; aminocarbazoles; aminoindoles; aminopyrroles;
amino-indazolinones; aminomercaptotriazoles; aminoperimidines;
aminoalkyl imidazoles, such as 1-(2-aminoethyl) imidazole,
1-(3-aminopropyl) imidazole; and aminoalkyl morpholines, such as
4-(3-aminopropyl) morpholine.
In a preferred embodiment, the compounds suitable for use as
antioxidants are prepared from succinimide-acids obtained by
reacting a low molecular alkyl or alkenyl succinic acylating
agents, preferably C.sub.8 -C.sub.70 alkenyl succinic anhydrides,
with an aromatic amino acid.
Preparation of Metal Detergent Additives
The pendant carboxylic acid moiety of the succinimide-acid compound
can undergo neutralization reaction with an alkali or
alkaline-earth metal oxide or hydroxide to result in a simple metal
salt. This neutralization reaction or the pendant carboxylic acid
moiety can also be performed in the presence of carbon dioxide
resulting in an overbased metal salt. When preparing compounds for
use as metal-containing detergents, it is preferred to use
succinimide-acid compounds derived from a low molecular alkyl or
alkenyl succinic acylating agents, preferably C.sub.8 -C.sub.100
alkenyl succinic anhydrides, more preferably C.sub.12 -C.sub.30
alkenyl succinic anhydrides and most preferably C.sub.16 -C.sub.26
alkenyl succinic anhydrides.
These sulfur-free additives are expected to be effective detergents
useful for lubricant formulations including crankcase, gear, CVT
and ATF applications.
Detergents in the lubricating oils suspend thermal decomposition
and oxidation products and reduce or retard the formation of
varnish and lacquer deposits.
The base fuels used in formulating the fuel compositions of the
present invention include any base fuels suitable for use in the
operation of spark-ignition or compression-ignition internal
combustion engines such as diesel fuel, jet fuel, kerosene, leaded
or unleaded motor and aviation gasolines, and so-called
reformulated gasolines which typically contain both hydrocarbons of
the gasoline boiling range and fuel-soluble oxygenated blending
agents, such as alcohols, ethers and other suitable
oxygen-containing organic compounds. Oxygenates suitable for use in
the present invention include methanol, ethanol, isopropanol,
t-butanol, mixed C1 to C5 alcohols, methyl tertiary butyl ether,
tertiary amyl methyl ether, ethyl tertiary butyl ether and mixed
ethers. Oxygenates, when used, will normally be present in the base
fuel in an amount below about 25% by volume, and preferably in an
amount that provides an oxygen content in the overall fuel in the
range of about 0.5 to about 5 percent by volume.
The base fuels used in formulating the fuel compositions of the
present invention include compression ignition fuels having a
sulfur content of up to about 0.2% by weight, more preferably up to
about 0.05% by weight, as determined by the test method specified
in ASTM D 2622-98. The preferred compression-ignition fuels for use
in the present invention are low sulfur content diesel fuels.
The base oils suitable for use in formulating lubricating oil
compositions to the present invention may be selected from any of
the synthetic or natural oils or mixtures thereof. The synthetic
base oils include alkyl esters of dicarboxylic acids, polyglycols
and alcohols, poly-alpha-olefins, including polybutenes, alkyl
benzenes, organic esters of phosphoric acids, and polysilicone
oils. Natural base oils include mineral lubrication oils which may
vary widely as to their crude source, e.g., as to whether they are
paraffinic, naphthenic, or mixed paraffinic-naphthenic. The base
oil typically has a viscosity of about 2.5 to about 15 cSt and
preferably about 2.5 to about 11 cSt at 100.degree. C.
The additives used in formulating the compositions of the present
invention can be blended into the base oil or fuel individually or
in various sub-combinations. However, it is preferable to blend all
of the components concurrently using an additive concentrate (i.e.,
additives plus a diluent, such as a hydrocarbon solvent). The use
of an additive concentrate takes advantage of the mutual
compatibility afforded by the combination of ingredients when in
the form of an additive concentrate. Also, the use of a concentrate
reduces blending time and lessens the possibility of blending
errors.
In one embodiment, the present invention is directed to a method of
improving the oxidation stability and retarding the rate of
viscosity increase, of a lubricating oil, wherein said method
comprises adding to a lubricating oil an oxidation stability
improving amount of the succinimide-acid derivatives of the present
invention, wherein said oxidation stability improving amount of
said succinimide-acid derivative is effective to improve the
oxidative stability of the lubricating oil, as compared to the same
lubricating oil except that it is devoid of said succinimide-acid
derivative. For improving the oxidation stability of the oil, the
succinimide-acid derivative is typically present in the lubricating
oil in an amount of from 0.1 to 3 weight percent based on the total
weight of the oil. Improvements in the oxidation stability of a
lubricating oil are evident by a reduction in the rate of oil
thickening of an oil containing the additives of the present
invention as well as a reduction in the amount of insoluble deposit
forming materials in the oil compared to a similar oil except that
it is devoid of said additive.
In one embodiment, the present invention is directed to a method of
improving the fuel economy of an internal combustion engine,
wherein said method comprises using as the crankcase lubricating
oil for said internal combustion engine a lubricating oil
containing the succinimide-acid derivative of the present
invention, wherein said succinimide-acid derivative is present in
an amount sufficient to improve the fuel economy of the internal
combustion engine using said crankcase lubricating oil, as compared
to said engine operated in the same manner and using the same
crankcase lubricating oil except that the oil is devoid of said
succinimide-acid derivative. For improving fuel economy, the
succinimide-acid derivative is typically present in the lubricating
oil in an amount of from 0.1 to 3 weight percent based on the total
weight of the oil.
In one embodiment, the present invention is directed to a method of
reducing deposits on a lubricated surface, wherein said method
comprises using as the lubricating oil for said surface a
lubricating oil containing the succinimide-acid derivative of the
present invention, wherein said succinimide-acid derivative is
present in an amount sufficient to reduce the amount of deposits on
said surface, as compared to the amount of deposits on said surface
subjected to the same operating conditions and using the same
lubricating oil except that the oil is devoid of said
succinimide-acid derivative. For reducing deposits, the
succinimide-acid derivative is typically present in the lubricating
oil in an amount of from 0.1 to 10 weight percent based on the
total weight of the oil. Representative of the deposits that may be
reduced using the compositions of the present invention include
piston deposits, ring land deposits, crown land deposits and top
land deposits.
In one embodiment, the present invention is directed to a method of
reducing wear in an internal combustion engine, wherein said method
comprises using as the crankcase lubricating oil for said internal
combustion engine a lubricating oil containing the succinimide-acid
derivative of the present invention, wherein said succinimide-acid
derivative is present in an amount sufficient to reduce the wear in
an internal combustion engine operated using said crankcase
lubricating oil, as compared to the wear in said engine operated in
the same manner and using the same crankcase lubricating oil except
that the oil is devoid of said succinimide-acid derivative. For
reducing wear, the succinimide-acid derivative is typically present
in the lubricating oil in an amount of from 0.1 to 3 weight percent
based on the total weight of the oil. Representative of the types
of wear that may be reduced using the compositions of the present
invention include cam wear and lifter wear.
At numerous places throughout this specification, reference has
been made to a number of U.S. Patents and published foreign patent
applications. All such cited documents are expressly incorporated
in full into this disclosure as if fully set forth herein.
This invention is susceptible to considerable variation in its
practice. Accordingly, this invention is not limited to the
specific exemplifications set forth hereinabove. Rather, this
invention is within the spirit and scope of the appended claims,
including the equivalents thereof available as a matter of law.
The patentee does not intend to dedicate any disclosed embodiments
to the public, and to the extent any disclosed modifications or
alterations may not literally fall within the scope of the claims,
they are considered to be part of the invention under the doctrine
of equivalents.
* * * * *